1. Field of Invention
The invention relates to pressure tap assemblies, and more specifically to a tap assembly which is stabilized such that tendency for leaking and/or failure by shearing is reduced.
2. Description of the Related Art
Pressure taps, such as used in a vessel, including a pipeline on one or both sides of an orifice plate, are useful to measure pressure in a conduit, such as a pipeline carrying liquid gaseous fluid, which pressure measurement can be used for various calculations, such as flow rate; metering, etc. The taps can be fluidly connected to a pressure sensor, which in some cases acts as a pressure transmitter. When used on either side of an orifice plate the high and low pressure measurements can be used as inputs to so-called “smart” differential pressure transmitters.
The taps themselves are standardized with NPT threads. By means of pipe fittings or manifolds the taps can be placed in fluid communication with pressure, or differential pressure, transmitters for purposes of providing information on the pressure of the fluid inside the conduit.
One of the shortcomings of the conventional taps has been the propensity of the load on the taps being transmitted to the NPT threads causing leaking of the fluid in the pipeline to escape to the environment. In cases where the pipeline is carrying combustible or explosive fluids, e.g. oil or natural gas, the escape of the fluid from the threads could also result in personal injury and damage to property. In extreme loadings, the NPT threads of the taps are stressed to their elastic limit resulting in shearing of the taps and release of the fluid in great quantities to the environment.
Thus, it is an object of the present invention to provide stabilized taps of a construction where the propensity of leaking of fluid through the NPT threads is reduced. It is also an object of the invention to provide a stabilized tap construction such that rocking of the taps are reduced, even when taps are subjected to external static and dynamic loads, such as weight of a transmitter and associated “plumbing”, e.g. manifolds, which are in fluid communication with the taps of the invention.
It is a still further object of the invention to provide new tap construction and function which will diminish the tendency of a tap to fail by either leakage past the NPT threads, or shearing of the tap itself due to external forces placed upon the tap.
These and other objects of the invention will become apparent by reference to the following description of the preferred embodiments and the appended drawings.